Search results for " elements"

The M4 transitions of isomeric states

2015

Tässä pro gradu -tutkielmassa tutkitaan isomeeristen tilojen magneettisten M4-gammasiirtymien redusoituja matriisielementtejä. Tutkittavat siirtymät ovat venyneitä M4-siirtymiä kaksoisbeetahajoamisten massa-alueilla A=85-115 ja A=135-143. Tutkielman tarkoituksena on verrata kokeellisia ydinmatriisielementtejä kvasihiukkasmatriisielementteihin ja MQPM-teorian avulla laskettuihin matriisielementteihin. Kokeelliset matriisielementi lasketaan kokeellisesti määritettyjen arvojen avulla ja kvasihiukkas- sekä MQPM-matriisielementit määritetään tietokoneohjelmien avulla. Kokeellisten ja kvasihiukkasmatriisielementtien välinen suhde osoittautui olevan noin 0,29 ja kokeellisten ja MQPM-matriisielemen…

Flavor physics in the quark sector

2010

218 páginas, 106 figuras, 89 tablas.-- arXiv:0907.5386v2.-- Report of the CKM workshop, Rome 9-13th Sep. 2008.-- et al.

Lattice-constrained parametrizations of form factors for semileptonic and rare radiative B decays

1997

We describe the form factors for B to rho lepton neutrino and B to K* gamma decays with just two parameters and the two form factors for B to pi lepton neutrino with a further two or three parameters. The parametrizations are consistent with heavy quark symmetry, kinematic constraints and lattice results, which we use to determine the parameters. In addition, we test versions of the parametrizations consistent (or not) with light-cone sum rule scaling relations at q^2=0.

Analytical and Numerical Methods for the Evaluation of Critical Conditions in Longitudinal Bars of RC Columns

2017

Buckling collapse of reinforcing bars in concrete members is usually observed in framed structures after severe earthquakes. Second order effects modify the compressive response of steel bars, reducing ductility and affecting the post-elastic branch. Literature investigations show that instability can involve more stirrups, or it can be limited to the pitch. If the critical length is not carefully estimated, transverse steel’s failure can be achieved in brittle manner, causing the sudden loss of confinement in the inner concrete. This paper presents the results of a theoretical investigation, aiming to evaluate the reliability of different approaches for calculating critical conditions of l…

Unraveling the role of the secretor antigen in human rotavirus attachment to histo-blood group antigens

2019

25 Páginas, 7 figuras, 2 tablas

Radiation responses of Yb/Er-doped phosphosilicate optical fibers: hardening mechanisms related to Ce-codoping

2012

International audience; In this paper, we investigated the origins of the Ce positive influence on the radiation response of Yb/Er-doped phosphosilicate optical fibers. To this purpose, we carried out during γ-irradiations an online characterization on active optical fiber prototypes, made with different Ce concentrations and integrated in optical amplifiers. The hardening effect of Ce-codoping is highlighted, as well as some aspects related to the radiation response of the phosphosilicate host glass of the active optical fibers.

A selective microscale x-ray fluorescence analyzing method for determination of trace elements

1973

Abstract A new selective X-ray fluorescence analyzing method for trace element determination has been developed. In this method each trace element is measured independently. The excitation source is an X-ray tube that has a changeable anode and a variable high voltage. The exciting radiation is shaped with critical absorbers. The sample is viewed at backward angles through an absorber to reduce backscattered radiation. The estimated accuracy of this method is of the order of 10 per cent in thesub-ppm range of trace element concentration in organic samples. Measurement times are of the order of a few minutes.

The impact of volcanogenic emissions of major and trace elements at Mt. Etna, Sicily, on precipitation (rain and snow) chemistry

2009

CHEMICAL COMPOSITION OF ATMOSPHERIC BULK DEPOSITION AT THE INDUSTRIAL AREA OF GELA (SICILY, ITALY)

2014

Bulk deposition has been collected at six sampling sites in area of Gela plain (Italy) in the period from February 2008 to May 2009. Samples collected each two weeks were analysed for the major ion and trace elements content. Preliminary results allow identifying three different sources that control the abundance of the elements in atmospheric deposition: (1) sea spray, (2)geogenic dust, and (3) anthropogenic pollution. Due to the closeness of the coast, clear evidence of sea spray input is detectable for most of the samples. The high excess of non sea-salt sulphate(50 - 90% of the total) is prevailingly ascribable to the abundant SO2 emissions of the refinery.The pH values of the collected…

Fission in the landscape of heaviest elements: Some recent examples

2016

The fission process still remains a main factor that determines the stability of the atomic nucleus of heaviest elements. Fission half-lives vary over a wide range, 10^−19 to 10^24 s. Present experimental techniques for the synthesis of the superheavy elements that usually measure α-decay chains are sensitive only in a limited range of half-lives, often 10^5 to 10^3 s. In the past years, measurement techniques for very short-lived and very long-lived nuclei were significantly improved at the gas-filled recoil separator TASCA at GSI Darmstadt. Recently, several experimental studies of fission-related phenomena have successfully been performed. In this paper, results on 254−256Rf and 266Lr ar…